The Peptide Sequencing and Amino Acid Analysis Shared Resource provides essentially four different services that include the analyses of N-terminal amino acid sequence, internal sequence and amino acid composition and the purification of peptides. Since September 1995, when the Cancer Center Support Grant was funded, this resource has served 38 different Cancer Center investigators (of a total of 74 investigators at Vanderbilt University). Over 317 samples have been analyzed for their peptide sequences and 402 amino acid compositions have been determined within the same time period. The overall usage by the Cancer Center investigators accounts for approximately 57.4 percent of the entire usage. This Resource will continue to provide the four existing services to meet the demand for the identification of peptides and for acquiring the basic knowledge of the structural information of peptides.